Apparatus for amplifying small movements



1927 F. G. CREED ET A1.

I APii RA-ius FOR AMPLIFYINQ SMALL MOVEMENTS Filed Jan. 29. 1921s" s Sheets-Sheet 1 F. G. CREED ET AL APPARATUS FOR AMPLIFYING SMALL MOVEMENTS Filed Jan. 29, 1926 I 3 Sheets-Sheet 2 1,639,839 1927' F. a. chasm ET AL APPARATUS FOR AMPLIFYING SMALL MOVEMENTS Filed Janl 1926 3 SheetsSheet 3 for effecting either directly,

z pressure responsive means to Patented Aug. 23, 1927.

UNITED f STA TEs FREDERICK un one]: CREED, or CBOYDON, AND AXEL 03mm, or s'mnn'rnm,

. 1 Lennon, ENGLAND.

APPARATUS FOR AMPLIFYING SMALL MOVEMENTS.

Application filed Januar ae, 1926, Serial No This invention has reference to improvements in apparatus for amplifying small movements, particularly those produced by small electrical forces occurring in electrical apparatus of various kinds, and it has,

for its object to provide apparatus for this purpose of a simple robust, compact and effective character. I I

For this purpose, .in. apparatus according thereto, there is associated with a device (hereinafter called the primary movable device) to which only small movements are imparted by forces impressed thereon, a re-. ceiver to which fluid under pressure is supplied at a suitable rate and which has an outlet for fluid controlled, as to rate of outflow, by the said primary movable device, secondary movable means responsive to variations in fluid pressure within the receiver and hereinafter called for distinction pres sure responsive means, and means hereinafter called for distinction. motion amplifying means, responsive to movement of the pressure responsive means andadapted to bring about an amplified movement of some device or indirectly through one or more additional amplifying devices or relays, that may be of a mechani cal or an electrical nature, some useful effect.

The arrangementis such that assuming fluid mined condition, but uponthe primary movable device being caused to move relatively to the outletof the receiver, it will retard or facilitatethe escape of fluid therefrom, as the case may be, and thereby vary the fluid pressure in'thereceiver and cause the act and operate the. motion amplifying means to produce some desired useful effect.

The primary movable device may form part, for instance, of anelectro-magnetic or electro-static device designed to be operated by electric impulses or signals. The electromagnetic device may, for example, form part of telegraphic apparatus ofthe kind. comprising a floating a vane,

movable coil, such as has been used for actuating asyphon recorder,

. 84,721, and in Great Britain February .5, 1925.

or a mirror galvanometer, but which in apparatus according to the present invention would operate a baffling. device, for instance blade orprojection, mounted opposite to but out of contact with the fluid outlet of the fluid pressure receiver so as to be in the path of the issuing jet of fluid in order that .flow thereof will be bafiled or checked to a definite extent and a predetermined normal pressure set up in the fluid pressure receiver when the baffling device is in its normal position, such normal pressure depend- .ing upon the rate of flow of fluid, which is maintained constant, into the receiver. With such an arrangement, when the baffling device moves from its normal osition towards the outlet of the receiver, t e fluid pressure in the receiver will be increased beyond its normal value, the pressure being restored to the normal value when the baffling device returns to its normal position. If the battling device moves from its normal position in a direction away from the outlet of the receiver, the flow of fluid from the receiver will be increased and the pressure in the receiver will fall below the normal value,-the pressure being restored to normal value when the baffling device moves back to its normal position.

The apparatus may thus be made'sin 1e a'cting, or doubleacting, according as t e prunary movabledevice is adapted to be .moved only from and towards itsnormal position, or to be moved from and towards its normal position in opposite directions from its normal position.

In the former case, the apparatus comprises a sin 1e fluid pressure receiver with fluid outlet and associated pressure responsive meansand motion amplifying means that move from and back to normal position. In the second case, the apparatus may comprise a single fluid pressure receiver with fluid outlet and ressure responsive means connected to motion amplifying means, as in the first case, but the pressure responsive means and motion amplifying means will be able to move alternatel or intermittently in opposite directions from a mid position andback to such mid position, that is to say, to oscillate. The baffling device can be held in its normal position, against the pressure of the issuing fluid thereon, in any convenient way, as by a spring, orby a torsional force applied to, the

means used for suspending or supporting the floating movable coil or equivalent, or by directing another jet of fluid similar to the first jet upon the opposite side of the battling device, so that the fluid pressure on the two sides of such device will be balanced when the device is in its mid or normal position. The second jetmay issue from an outlet nozzle connected to the same fluid pressure supply pipe as the first outlet nozzle. In some cases, the second outlet nozzle may extend from a second fluid pressure receiver provided with pressure responsive means and associated motion amplifying means.

The primary movable device instead of being arranged to move towards and from the outlet may be arranged to move transversely to the outlet.

The fluid pressure receiver comprises a chamber which may conveniently be formed by and between two circular walls, one stationary and provided with a fluid outlet nozzle, and the other movable and constituted by a piston which should be adapted to be moved axially with the minimum of friction and which constitutes the pressure responsive device, Or the movable wall of the chamber may be constituted by a flexible diphragm of suitable material, for example rubber, connected to the periphery of the stationary wall, such flexible diaphragm forming the pressure responsive device. The fluid pressure chamber thus formed may be provided with means. for instance an adjustable screw or valve, for regulating, the normal supply of the fluid thereof fluid from the outlet of the next chamber the piston or diaphragm of which is adapted in like manner to control the exit of fluid from a third chamber and so on, the piston or diaphragm of the last chamber being arranged to actuate or control. mechanically, electrically. or otherwise, the device by which the magnified movements of the primary i Fig. 1 is a side elevation,

movable device are to be detected and utilized. In this case the pressure of the fluid admitted to the successive chambers may be different in the various chambers if desired. Or the pressure of the fluid supply may be maintained constant and the chambers be of successively increasing diameter.

As will be obvious, apparatus of the kind referred to, adapted to operate in the manner set 'forth, can be constructed in various forms and be used for various purposes.

In the accompanying illustrative drawings, Fig. 2 a plan and Figs. 3 and end elevations, showing one construction of apparatus according to the invention, suitable for operating the recording syphon of a telegraphic instrument. Fig. 5 shows in longitudinal vertical section, one of the fluid pressure cylinders with associated pressure responsive device, used n the said apparatus. Fig. 6 is a diagrammatic view of a syphon recorder and the means for directly operating it. Fig. 7 is a diagrammatic view showing a modification. llig. 8 shows a further modified construction.

In the example shown in Figs. 1 to (3 inclusive, there are three fluid pressure receivers a fixed to'the top of a con'ipressed air chamber 72 having a con'ipressed air inlet 0 and carried by a hollow base plate the bottom of the air chamber being formed by a plate 6 soldered in place. Each receiver ais constituted by a metal body (see F 5) having therein a cylindrical cavity provided at one end with astationary wall a and fitted with an endways movable piston y, the space bet-ween the wall, piston and. surrounding wall of the casing forming a compressed air chumber a that is in conununication with the compressed air supply cham her 5 through a passage 7L fitted with a rcmovable nozzle 2'. The front wall 0 provided with a fluid outlet nozzle j through which compressed air will issue from the chamber a is is a bathing device arranged opposite the air outlet nozzle j of the firyt receiver a. It consists of a vane carried by a floating coil m adapted to be connected to an electric land line or submarine cable and arranged between the poles N S of an electro-magnet n, a stationary iron core it being arranged within the coil. The vane is held in its normal position by a slight torsion applied to the suspension means 0 of the coil m whichmay, as shown, he of the usual bifilar construction. m is a spring to steady the coil. To the piston g is connected a rod 9* the outer end of which is provided with a baffling device 8 in the form of a disc provided with a sleeve s 'by which it can be fixed to the rod. The baffling device a is arranged opposite the air outlet nozzle 7' of the second compressed air receiver a the piston of which is similarly provided with a rod 9' carrying a baffling device 5* arranged opposite the air outlet nozzle 7' of the third compressed air receiver a. The piston of the latter receiver is similarly provided with a rod 7' having at its outer end a device t similar to the baffling devices 8. but ;which acts as an abutment for one end of a thrust rod 10 the other end of which acts against an for supporting the syphon 5 of an ordinary syphon recorder. 2" is a spring connectedto the lever arm 2 and adapted normally to balance the opposing action of the lever o and hold the syphon in its normal midposition 6 in the ink well for the syphon and 7 a roller over which passes a tape 8 upon which telegraph signals are recorded by the syphonin the ordinary way. In the example shown, the compressed air chambers a in the successive receivers a and the mo-vable pistons g therein, are'made of increasing diameter from left to right, airof the same pressure being admitted to each chamber, so that the force exerted the successive pistons will be of increasing value.

' Or, for a like purpose, the several compressed air chambersa; and the pistons 9 could be made of the same diameter and air at successively increasing pressure be admitted to the several chambers a 7 The arrangement is such that normally, the baffling vane 70, the bafflingdevices s and abutment device t will beheld in their the air supplied to the compressed air chambers a and the size of the outlet passages in the nozzles, the Whole forming a balanced system. When a telegraph signal or impulse is received by the movable coil" m, the vane It will be caused by the coil to move, either towards or from the compressed air nozzle 7' of the first compressed air chamber a depending upon the sign, positive or negative, of the signal, and will in consequence either baffle the air flowing out of the nozzle j of the first 'receiver'a to a greater extent than before, so as to increase the air pressure in the chamber e or will exert a less baffling actionon the issuing air and permit the air pressure in the chamber a? to fall. piston g in the first chamber a to move to the right or left as the case may be, and

cause its bafliing device 8 to act on the air issuing from thenozzle y of the second chamber a in a similar manner to the vane 7c in relation to the air issuing from the nozzle of the first chamber a of the second chamber will consequently be caused to move to the right or left and cause its baffling device s'to act in like manner on the air issuing from the nozzle j of the third chamber. The piston of the latter chamber will consequently either move the motion Theresult will be to cause the i The piston amplifying lever 11 through the abutment device t and thrust rod to to the right and move the recording end of the syphon 5 in one direotion on the recording tape 8 against the action of the springs 3 and 2, or will allow the said lever *21 to be moved to the left by the action of the said springs so as to cause the free end of the syphon 5 to move inthe opposite direction on the recording tape.

In order that each piston g may move" freely to and fro within the cylindrical cavity of its respective body or casing a, soas practically to eliminate sliding trictiom'it 'may be made slightly smaller in diameter than the cavity, say one thousandth of an inch less in diameter, andbe supported by its rod 1' in the upper ends of two sprin blades 9 and 9* in such manner that it toes not touch the body or casing a;

Fig.7 shows diagrammatically, a modified' 's5 g, as hereinbetore described, the stationary wall being provided with a fluid outlet nozzle j to which is connected a branch air supply" pipe j provided with a regulating valve or screw 7' for controlling the rate of flow of air under pressure into the chamher. the outlet nozzle, consists of a vane carried by a floating coil m, as in the arrangementhereinbefore described.

In this example two fluid pressure chambers a are shown. of the flexible diaphragm g of the first chamber a is arranged to act as a baffling device for the air issuing 'from the outlet nozzle j of the next chamber a as and for the purpose hereinbefore" described. To

the centre of the flexible diaphragm 9 of "the second and last chamber a is connected to one endfiof a length 10 of flexiblematerial, for instance silk fibre, the other end of which is connected to a stationary holder 11. To an intermediate point 10 of the length 10 of flexiblematerial is connected one end of another length 12 of similar material the other end of which is fixed to another stationary holder 13. To an point 12 of this secondlength 12 of flexible material connected one end of a straight length 14 of similar material the other end of which is connected to one end of a lever 15',' carrying a recording syphon 5. The other end of the lever may be connected to a spring 16. Or the syphon may be sup- Thc baffling device arranged opposite The central portion 8 intermediate ported by a bifilar suspension through a 7 pin that is connected to the straight length r and 12 of flexible material is held in a bent or angular position, as showmand normally,

the syphon 5 is held in its mid position, and

that by movement of the vane to and fro past its mid or normal position, opposite the outlet nozzle 7' ot' the lirst fluid pressure chamber in accordance with received electric signals or impulses, the flexible diaphragm y will be moved to and fro controlling the action of the diaphragm g of the second fluid pressure chamber and, through the mot-ion amplifying means, constituted by the lengths 10 and 12 of flexible material, and amplifying movement oi the syphon 5 to and fro across its midposition. on the tape 8 will result, in accordance with the said electric signals or impulses received. The flexible diapln'agm g oi? the fluid pressure receiver, or of the last receiver, could of course be connected to a motion amplifying lever like that shown in Figs. 1 to 4:.

In arrangements such as described, the dimensions of the fluid pressure chamber a controlled by the primary movable de vice such as the vane k, and its outlet, such as the nozzle j, will usually be small. For instance, the diameter ol the chamber may be of the order of say one inch, the axial distance between the fixed and movable walls, when the latter is subjected to air pressure, be of the order of say one thirty-second of an inch and the diameter of the air passage in the outlet nozzle be of the order of say one hundredth of an inch, so that the cross sectional area of the passage in this outlet nozzle in relation to that of the piston or flexible dia hragm will be as one to ten thousand. Y en several fluid pressure receivers are used, the diameter of their several chambers M, if the pressure of the air supplied to each chamber be maintained con stant, may for example be in the ratio of 1, 1.25, 1.5. The supply pressure of the fluid used, namely air, may for example, be two or three pounds to the square inch. The inner face of the stationary wall of the receiver chamber, or of each receiver cham her, when a flexible diaphragm is used, may, as shown in Fig. 7, be of a flattened conical or convex shape, and the movement 01"; the

central portion of the flexible diaphragm in relation thereto may be of the order of say about one hundredth of an inch. Each of the two lengths 10 and 12 of flexible material (Fig. 7), when such is used, may for example be about six inches long. The dimensions of the various parts can however be varied according to the period and the amplitude of movement o'tthe primary movable device and the magnification desired.

Apparatus according to the invention can advantageously be used in connection with land line, ocean cables and wireless telegraphic apparatus for operating, through electric relay arrangements, other telegraphic apparatus for reproducing, in amplified form, Weak electric signals or impulses. Thus, the free end of thelever *1) may, for the purpose just mentioned, be arranged to work between contacts 17 and 18 of an electric relay as shown in. Fig. 8.

lVhat we claim is:- V

1. For amplifying small lllOVOIIlOl'll'S, apparatus comprising a fluid pressure receiver having an inlet and an outlet tor fluid under pressure, a movable device, subject to small forces, arranged opposite to and at all times out oi? contai't with the outlet olf said re ceiver and adapted by its umvement to control the exit of fluid therefrom and pressure responsive means subject to variations of fluid pressure within said receiver and means responsive to movement of said pressure responsive means.

2. For amplifying small. movements, apparatus comprising a fluid pressure receiver having an inlet and an outlet for fluid under pressure, movable bailling means subject to small forces. arranged opposite to and at all times out )f .COlll'2l(it with said outlet and adapted by its movement to control the exit. of fluid from said receiver, pressure responsive means subject to variations of fluid pressure within said receiver, and motion amplifying means responsive to movement of said pressure responsive means.

For amplifying small movements, a

fluid pressure receiver having an inlet and' an outlet for fluid under pressure, a movable battling means arranged opposite to and at all times out of contact with the said outlet and adapted by its moven'ients to vary the exit of fluid from said receiver, means adapted to actuate said baiiling means and subject to and, movable by small forces applied thereto, presure responsive means subject to variations oi fluid pressure within said receiver and motion an'ipliiying means responsive to movement of said pressure re sponsive means.

4:. For amplifying small movements, a fluid pressure receiver having an inlet and an outlet for fluid under pressure, movable baflling means arranged opposite to and at all times out of contact with said outlet and adapted to vary the exit of fluid from said receiver, means subject to small electrical forces of a varying nature, adapted to actuate said bafliing means, and pressure responsive means subject to variations of fluid pressure within said receiver.

5. For amplifying small movements, a fluid pressure receiver having an inlet and an outlet for fluid under pressure, movable baflling means arranged opposite to and at all times out of contact with said outlet and adapted by its movement to vary the exit of fluid from said receiver, telegraphic apparatus embodying; a movable member responsive to small electrical forces applied thereto, connected to and adapted to actuate said battling means, pressure responsive means baffling means arranged opposite to and at all times out of contact with said outlet and adapted byits movement to vary the exit of fluid from said receiver, telegraphic apparatus having a movable coil responsive to small electrical forces applied thereto, connected to and adaptedto actuate said baflling means, pressure responsive means subject to variation of fluid pressure ithin said receiver and motion amplifying meansresponsive to movement of said pressure responsive means; i

7. For amplifying small movements, a fluid pressure receiver having an inlet and an outlet for fluidunder pressure, movable bafliing means arranged oppositefto and at all times out of contact With said outlet and adapted by its movement to vary the exit of fluid from said receiver, telegraphic apparatus having a movable member responsive to small-electrical forces-applied thereto and'connected to'said baflling'means, yielding means adapted normally to hold said baffling means in a mid position of movement, pressure responsive. means subject to variation of pressure Within said receiver and motion amplifying means respon sive to movement of said pressure responsive 8. For amplifying small movements, a fluid pressure receiver having an inlet and an outlet for fluid under pressure, movable bafliing means arranged. opposite to and at all times out of contact With said outlet and adapted by its movement to vary the exit of fluid from said receiver, telegraphic apparatus having a movable member responsive to small electrical forces applied thereto and connected to said baffling means, yielding means adapted normally to hold said baffling means in a mid position of movement, pressure responsive means subject to variation of pressure Within said receiver, motion amplifying means responsive to movement of said pressure responsive means and means adapted to utilize the movement of said motion amplifying means] i 9. For amplifying small movements, apparatus comprising a fluid pressure receiver having an inlet andan outlet for fluid under pressure, a movable device, subject to small forces, arranged opposite to and at all times out of contact With the outlet of said receiver and adapted by its movement to control the exit of fluid therefrom, a piston mounted to reciprocate Within said receiver in response to variations of fluid pressure therein and motion amplifying means responsiveto t themovements of said piston.

10. Afluid pressure receiver having an inlet and an outlet for fluid under pressure, a p1ston arranged ithin but of slightly, less,

diameter than said receiver and means for} supportingsaid p1ston JIL such maimerfthat I it is axiall movable in response-to varying pr direct'sliding contact With said receiver. 7

11. A fluid pressure receiver having an inlet and an outlet for fluid'under pressure,

a piston arranged Within but of sligitly less diameter than said receiver and sprin -means adapted tosupport said piston in suc '1 mans'ure Within said receiveifbut is outof ner that itis axially 'movable'in response to varying fluid pressure Within"said receiver but is out of direct sliding contact with said I receiven. j j

12. For. amplifying small movements,

apparatus comprising a plurality of fluid pressure receivers each having an inlet and" an outlet for fluid under pressure, a piston mounted Within'each of said receivers and each axially movable in response to variations of fluid pressure Within its receiver, a

movable baffling device arranged oppositely to andv at all times out of contact With the outlet of each cylinder, the baffling device of the first receiver being subject to small forces to'be utilized and the baffling device of each succeeding receiver being movable by the piston in a preceding receiver and means res onsive to the movements of the piston of t e last receiver of the series.

13. For amplifying small movements,

apparatus comprising a plurality of fluid" pressure receivers each having an inlet for fluid under pressure and an outlet nozzle for said fluid, an axially movable spring controlled piston mounted in each receiver so as to be out of direct sliding contact therewith and responsive to variations of fluid pressure therein, a baffling device mounted opposite to and at all times out of contact W1th the outlet nozzle of each receiver,-the baflling device for the first receiver being adapted to be actuated by small forces to be utilized, and the baflling device of each succeeding receiver being actuated by the piston of a preceding receiver, and motion amplifying means responsive to the movements of the piston of the last receiver.

14. For amplifying small movements, apparatus comprising a plurality of fluid pressure receivers of successively increasing cross sectional area and each having an inlet for fluid under pressure and an outlet ofvery 7 small cross sectional areacompared to that of 1ts recelver and through Wh1ch fluid can flow, a fluid pressure supply chamber comtherein, a movable coil subject to electric i forces of small value means for normally holding such coil in a mid-position of move ment, a movable battling device-mounted opposite to and at all times out of contact with the outlet of each receiver, the baflling device for the first receiver being adapted to be actuatedby said movable coil and the baffling device for each succeeding receiver being actuated by the piston of the preceding receiver, and motion amplifying means re sponsive to the movement of the piston of the last receiver.

15. The combination with apparatus according to claim 14; of means-controlled by said motion amplifying means and adapted to utilize the movements thereof for effecting some useful purpose.

16. The combination with apparatus according to claim 14, of an electric relay actuated by said motion multiplying means.

17. An automatic control device comprising a cylinder having inlet and .outlet paS- sages for fluid under pressure and a movable end wall constituted by a floating piston and means for controlling the exit of fluid through said outlet, the movable end wall being responsive to variations of fluid pressure set up in said cylinder. 4

18. An automatic control apparatus comprising a cylinder having inlet and outlet passages for fluid under pressure, movable bafiling means for controlling the flow of fluid through said outlet passage, a piston made of slightly smaller diameter than the interior of said cylinder and having a rod extending from one side thereof and a pair of spring blades fixed at one end and having their other ends engaging said rod and acting to hold said piston out of contact with said cylinder.

Signed at Paris, France this 18th day of January 1926.

FREDERICK GEORGE CREED. AXEL ORLING. 

